Fork lift type bale stacker



Sept. 25, 1962 Filed July 26, 1960 I. DALE ETAL FORK LIFT TYPE BALE STACKER 7 Sheets-Sheet l INVENTORS WILD DALE NHHRLES .BJJEW/J P 1962 l. DALE ETAL 3,055,514

FORK LIFT TYPE BALE STACKER Filed July 26. 1960 '7 Sheets-Sheet 2.

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FORK LIFT TYPE BALE STACKER Filed July 26, 1960 7 Sheets-Sheet 6 Fig.5 +F 9 Z; 3 30 72 1 Nil 50 50 i 11 ,6 l6 16 CHHRLES -B Se t. 25, 1962 1. DALE ETAL 3,055,514

FORK LIFT TYPE BALE STACKER Filed July 26, 1960 '7 Sheets-Sheet 7 Fig.

INVENTOR l/VG URL 0 D Z E CHHELES 5 EW/J Mir United States Patent Oflice Patented Sept. 25, 1962 3,055,514 FORK LIFT TYPE BALE STACKER Ingvald Dale and Charles B. Lewis, Hoquiam, Wash, assignors to Lamb Grays Harbor Co., Inc., Hoquiam, Wash.

Filed July 26, 1960, Ser. No. 45,382 Claims. (Cl. 214-6) This invention relates to what are designated as bundle or bale stackers. More particularly, it relates to a stacker, for pulp bales or the like, designed for use in conjunction with a feed conveyor, whereby the bales to be stacked are delivered successively thereto, and an ofifbearing conveyor, or carrier, onto which the stacks, as formed, are delivered by the bale stacker and are transfer-red to points for easy pick up and conveyance to places of storage or use.

It is the principal object of this invention to provide a stacking mechanism for pulp bales or the like, which embodies, as one of its principal parts, a fork type lift device whereby the bales, as successively delivered to the stacker by the feed conveyor, may be individually picked up in the operation of assembling them into stacks and whereby each stack, upon its being formed, may be lifted and transferred by the fork lift to the off-bearing conveyor or other carrier employed with the mechanism.

More specifically stated, the objects and advantages of the present invention reside in the devices employed for effecting and controlling the sequence of operations of the iork lift mechanism for the reception and lifting of the bales for their assembly into stacks and tor the transfer of the stacks, as formed, to the off-bearing carrier.

It is a further object of this invention to provide a stacking mechanism that is pivotally mounted at one end for a horizontal, oscillating movement between a receiving position, at which it receives the bales and assembles them into stacks, and a stack discharging position, at which the stacker is directed at an angle relative to its position at the bale receiving station.

Further objects and advantages of the present invention reside in the specific devices for control of the various stacking mechanisms; in their relationship, and in their mode of operation or use in the bale stacking and stack conveying operations, presently to be described.

In accomplishing these above mentioned and other objects of the invention, We have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

FIG. 1 is a perspective view of the present stacker, as associated with a bale feed conveyor, showing the fingers of the fork lifit mechanism in their fully lowered position for reception thereon of a hale as delivered by the feed conveyor.

FIG. la is a schematic, plan view showing, at a reduced scale, the usual relationship of stacker and feed conveyor in forming a stack and indicating the swinging movement of the stacker between its bale receiving and stack unloading positions.

FIG. 2 is a perspective view of the bale stacker showing the bale first received from the feed conveyor for the formation of a stack, after having been lifited to a position permitting the next delivered bale to be advanced to a stopped position direct-1y beneath it.

FIG. 3 is a side elevation of the stacker with the fork lift mechanism in its fully raised position; this view showing that side of the stacker opposite that seen in FIGS. 1 and 2.

FIG. 3a is an enlarged cross-sectional view showing the pivotal mounting of the stacker at one end, this section being taken on line 3a--3a in FIG. 4.

FIG. 3b is a sectional detail through the base structure of the machine, on line 3b-3b shown in FIG. 3.

FIG. 4 is atop, or plan, view of the stacker with fork lifit extended.

FIG. 4a is an enlarged sectional view, taken in the vertical plane of line 4a4a in FIG. 4.

FIG. 5 is a vertical crosssection, taken substantially on line 5--5 in FIG. 3.

FIG. 6 is a horizontal section, taken on line 6-6 in FIG. 3 showing the fork lift power cylinder.

FIG. 7 is an enlarged, crcss sectional detail, taken on line 77 in FIG. 4.

FIG. 8 is an end elevation of the stacker, as viewed from its swinging end.

FIG. 9 is an enlarged, horizontal section taken on line 99 in FIG. 8 showing parts at the bale receiving end of the stacker, particularly showing the bale actuated switch lever.

FIG. 10 is an enlarged sectional detail taken on line Iii-10 in FIG. 9.

FIG. 11 is an enlarged vertical section taken on line 1 1 -111 in FIG. 4, showing a bale actuated fork carriage control switch and its actuator lever.

FIG. 12 is a schematic layout of the electrical and hydraulic systems employed in the operation of the machine.

Referring more in detail to the drawings and, first, particularly to FIGS. 1 and 1a; the stacker, herein designated in its entirety by reference numeral 10, is there shown in a position to receive bales b from a roller type conveyor mechanism 11, herein designated as the feed conveyor, and which stacker, by swinging through a horizontal arc of as indicated in FIG. 1a, is adapted to deliver each stack, as formed thereon, to an off-bearing conveyor 12 shown in that view. The base frame structure of the stacker is rigid and of rectangular formation, in plan. It is designated generally in FIG. 1 by reference numeral 10b. At its right hand end, the stacker, as observed best in FIGS. 3 and 4, is fixedly supported by a pivot member 13, and at its opposite end, is equipped at opposite sides with a pair of supporting caster wheels 1414 that are so positioned as to provide for the easy arcu-ate swinging of the stacker, by means presently described, about the pivot point :13, as previously mentioned.

The rectangular base structure 10b of the stacker mounts thereon, directly above it, the fork lift mechanism which is a characterizing part of the present invention, and which is designated in its entirety in FIG. 3, by reference character F. This mechanism comprises a rectangular frame structure 15 supported horizontally and parallel with and directly above the base structure 1%, by two pairs of crossed and pivotally joined levers 16--16; these levers being located at opposite sides of the machine and having their right hand ends, as shown in FIG. 3, pivotally mounted on cross-shafts 17 and 17x that extend in the same vertical plane between the opposite side forming members of the frame structures 10b and 15, and at their opposite ends are horizontally movably and pivotally joined with the opposite side members of these frames, as has been shown in FIG. 3b wherein it is shown that the ends of paired levers 1616 at opposite sides are joined by a cross rod 18, which at its ends, mounts rollers 19--19 which have guided horizontal travel in trackways formed by and between parallel rails 20-20 fixed to the inside surfaces of the opposite side members of the base frame 10b, and upper frames 15 as in FIGS. 3b and 7.

The paired sets of levers 1616 are pivotally joined at their crossing points, as shown in FIG. 6 by stub shafts 2121 extended in horizontal axial alignment from opposite ends of a cross-head 22.

The means for controlling this scissors lift will presently be fully described. The horizontal base frame structure 15 of the fork lift mechanism has a flat top surface 15! and has parallel opposite sidewalls 15s with vertical outside surfaces as well shown in FIG. 5. Mounted for reciprocal travel lengthwise on this frame structure 15 is the fork carrier frame which is shown in FIGS. 1, 2 and 3 to comprise a plurality of horizontal bars 24 that extend transversely across the top surface of frame 15 and beyond opposite sides thereof where they are joined rigidly to the top flanges of angle bars 25-25 that are so fixed as to extend along opposite sides of frame 15 as in FIG. 4. The vertical flanges 25v of these angle bars, at the inside thereof and adjacent their opposite ends mount rollers 29, see FIG. 3, which are disposed to travel between track forming rails 30-30 that are fixed horizontally to the outside faces of the side members of frame 15, as in FIGS. 3 and 5, thus to provide for support of the carrier frame 22 and its easy reciprocal action along the frame 15, as will presently be explained.

Fixed to the undersides of the several transverse bars 24, at the inside edges of the angle plates 25-25, as seen in FIG. 4, are the flat, load lifting fingers 32-32 of the fork lift structure, these being located, as has been well shown in FIGS. 1, 2 and 3, to extend in parallel relationship in the same horizontal plane. The reciprocal action of this carrier frame provides for the movement of the fingers relative to the top frame 15 from the position of extension, shown in FIG. 4, to the position of retraction as indicated in dash lines in that same view.

The means for effecting the reciprocal movements of frame 22 for extension and retraction of the fingers 32 of the fork lift comprises an elongated hydraulic cylinder 35, shown in FIG. 3, that is mounted above and lengthwise of frame 15. It is shown to be fixed at its right hand end in a bracket 36 that is fixedly mounted on the right hand end of frame 15 in the central longitudinal line of the machine. This cylinder has a piston rod 35r extended from the opposite end which, at its outer end, is attached to a bracket 37 that is fixed to the cross-rods 24 of the fork carrier frame. Oil under pressure is adapted to be selectively admitted to the opposite ends of the cylinder 35 under control of solenoid valves 38-38 shown in FIG. 12, as will presently be further explained, to shift the carrier frame as required to extend or retract the fork fingers.

The raising and lowering of the fork carrier frame 15 is effected by a hydraulic cylinder 40 that is supported horizontally, by a fixed connection at its inner end with cross-head 22, between the paired sets of crossed levers 16-16 at the level of the transversely aligned pivot pins 21-21 as shown best in FIGS. 3 and 6.

This power cylinder 40 is operated by oil under pressure as presently explained, under control of solenoid operated valves 42-42. A piston rod 43 extends from the inner end of the cylinder through an opening on the crosshead 22 and is equipped at its outer end with a cross-head 44 which is shown in FIG. 6, to have stub shafts 45-45 extended laterally therefrom, each mounting paired cam follower rollers 46-46 thereon which operate in rolling contact with and between cam plates 47-47 that are fixed, respectively, to the underside of frame 15 and top side of frame 10. This arrangement of hydraulic cylinder 40, rollers 46-46 and cam plates provides that the top frame 15 will be raised and lowered in accordance with the retracting and extending of the piston rod 43 under control of valves 42-42.

At its forward end; that being the end at the left in FIGS. 3 and 4, or at the right in FIGS. 1 and 2, two vertical stop bars 50-50 are rigidly fixed to the base frame b. These extend upwardly between the two fork fingers 32-32 as shown, to a bale stopping height or distance that is somewhat above the level of the fork fingers. When the fingers are extended they project substantially beyond the stop bars as in FIG. 3. When retracted, they terminate within these stop bars.

At one end, the base frame 10b is mounted byfthe vertical pivot member 13. This is fixed to a base plate 55 which is suitably fixed to the supporting surface. The pivot 13 is disposed somewhat laterally of the center line of the base frame, as will be noted by reference to its showing in FIG. 4. The swinging action of the stacker, as supported by pivot pin 13, and casters 14-14 is effected by a hydraulic cylinder 60 which is located immediately beneath frame 10, as seen in FIG. 3. This cylinder is pivoted at its left hand end, as seen in FIG. 3, to a bracket 61, fixed to the floor. A piston rod 62 extends from the swinging end of the cylinder 60 and this has a pivotal connection at its outer end as at 63, with a pivot bolt 64 that is contained in a bracket 65 fixed to the end member of frame 1% at the center line thereof; the connection being such that when the piston rod 62 is caused to be retracted, the stacker will be bodily swung about pivot 13, as from full line position to the dash line position of FIG. la. When the rod is caused to be extended, the stacker Will be swung from the dash line position of FIG. la, back to the full line position. For these movements of the piston rod, air is selectively admitted to one or the other of the ends of the cylinder 60 while exhausted from its opposite end; this operating air being under control of solenoid valves 70-70 shown in FIG. 12 and which are controlled, as will presently be explained.

The normal mode of operation of the stacker when assembled with the bale and stack conveyors as shown in FIG. 4 is as follows:

Assuming that the fork lift has been fully lowered and the stacker is properly aligned with the feed conveyor 11, the first advancing bale b on conveyor 11 is advanced over the lowered fingers 32 and engaged firmly against stop bars 5% as in dotted lines in FIG. 1. As it engages these bars, the bale also engages and actuates a pivotally mounted switch lever arm 72 that is shown in FIGS. 3, 8 and 12 to have a contact portion extend vertically between and slightly forwardly of the stop bars. The actuation of lever 72 by the bale operates to close a switch 73 mounted at the forward end of base frame 15. This switch energizes the solenoid valve 42 to admit pressure medium to the forward end of hydraulic cylinder 40 and the cylinder then operates to retract its piston rod and thus effect the opening of the paired scissors levers 16-16 and by that action to cause the lifting of the fork fingers and bale thereon from lowered to the FIG. 2 position. The up travel of the fingers is stopped by contact with limit switch 74. A second entering bale b now moves on conveyor 11, beneath the lifted bale into firm contact with the stop bars 50-50 and it likewise actuates the switch lever 72 which now effects lowering of the frame '15 and fork lift structure F to lower the lifted first bale to rest on the top of the second received bale. As this second bale lowering takes place, a switch lever 80 supported by and extended along one of the fork fingers 52 as in FIG. 11 is actuated by its contact with the top of the second bale and its movement operates to actuate a switch 82 on the fork which operates to apply pressure medium to cylinder 35 to retract the carriage 25 and fingers to their fully retracted positions.

When the carriage reaches its fully retracted position, it engages and actuates a switch 75 which operates to effect the lowering of the lift fork structure F to its fully lowered position at which it actuates a limit switch 76 to cause the extending of the fingers beneath the second received bale. When the forks reach fully extended position they actuate a limit switch 77. This cycle of operation is repeated until the stack of bales has reached a predetermined height, then the stacker is caused to be swung to stack discharge position by application of hydraulic medium to cylinder 60 and the stack is then lowered onto the off-bearing conveyor or other suitable carrier and thereafter returned to receiving position. The swing travel is stopped by contact with limit switch 78 which also causes the forks to lower to deposit the stack on the ofibearing conveyor. Down travel of the forks is stopped by actuation of limit switch 76 which also causes the forks to be retracted by directing hydraulic pressure medium to cylinder 35.

When the forks are fully retracted, limit switch 75 is actuated to swing the stacker back to stacking position. The swing return travel is stopped by actuation of limit switch 79 which also causes the forks to be extended. The machine is then ready for the next stacking cycle.

The present mechanism may be employed in various ways and with various conveyor arrangements, and it is not the intent that the claims shall be construed as limited to the present illustrations.

What We claim as new is:

1. A bale stacker comprising a base frame, stop means against one end of said base frame against which bales may be advanced, a bale lift mounted on said base frame, said bale lift comprising a carriage mounted for horizontal, reciprocal movement toward and from said stop means, bale pick-up fingers mounted on and extending horizontally from said carriage and movable therewith, a first power means actuated incident to the advancement of each bale against said stop means for raising said bale lift and to elevate the stopped bale on said pick-up fingers to a level that permits the next incoming bale to be advanced against said stop means, first control means actuated by said next incoming bale to cause said first power means to lower the bale lift and the lifted bale onto the last stopped bale and a second power means actuated incident to the lowering of the lifted bale to move the carriage away from said stop means and thereby retract said bale pick-up fingers from between the stacked bales, a second control means to actuate said first power means to lower said carriage to starting level and a third control means to actuate said second power means incident to the lowering of said carriage to move said carriage toward said stop means and said fingers below the stacked bales.

2. A bale stacker according to claim 1 wherein said base frame is pivotally supported at one end for horizontal swinging travel and is equipped at its swinging end with supporting wheels, and a third power means for swinging said base frame through the arc of travel.

3. A bale stacker, as recited in claim 1, wherein said base frame includes a scissors lift mechanism and said first power means is a power cylinder operable to control the lifting and lowering operations of said scissors lift mechanism.

4. A bale stacker according to claim 1 wherein said stop means is fixed to said base frame at one end thereof and said base frame is pivoted at the end opposite said stop means for horizontal swinging between a bale receiving position and a stack discharge position, and wherein a power cylinder is operable for effecting the swinging movements of said base frame between said positions, and a third control means is supported in a fixed position relative to said base frame, and is operable by a contact of the stacked bales therewith, when the stack reaches a predetermined height, to energize the power cylinder to swing the stacker from bale receiving to stack discharge position.

5. A bale stacker comprising a base frame equipped with a supporting pivot at one end mounting said stacker for arcuate swinging travel on a horizontal supporting surface, between a bale receiving position and a stack discharge position, a power cylinder having a fixed connection at one end with said supporting surface and at its other end with said base frame for effecting the swinging travel of said bare frame, a bale lift mechanism supported on said base frame by a lift device, a power cylinder for the actuation of the lift device to move the bale lift between bale receiving level and a stacking level, said base frame having stop bars fixed vertically thereto at its swinging end against which entering bales engage for individual pick-up and stacking, said bale lift mechanism including a carriage supported by said lift device and mounted for guided, horizontal, reciprocal travel, bale lifting forks secured to and extended from said carriage at one end thereof, and movable thereby to an extended position for the pick up thereon of a stopped bale, and to a retracted position for withdrawal of the forks from between stacked bales, power means for causing reciprocal movement of the carriage, actuating means engageable by a stopped bale to energize the lift device to elevate the stopped bale to a level sufficient for reception of the next oncoming bale beneath it, and said actuating means being energized by the next entering bale to lower the lift device to deposit the lifted bale upon the stopped entering bale, and a second actuating means energized by said lift device upon lowering to bale stacking position to retract the forks from between the stacked bales and then to eifect lowering of the lift and the extending of the forks to pick-up position.

Neja Apr. 24, 1951 Thomson Jan. 27, 1959 

